Along an assembly line, diapers and various types of other absorbent articles may be assembled by adding components to and otherwise modifying an advancing, continuous web of material. For example, in some processes, advancing webs of material are combined with other advancing webs of material. In other examples, individual components created from advancing webs of material are combined with advancing webs of material, which in turn, are then combined with other advancing webs of material. Webs of material and component parts used to manufacture diapers may include: backsheets, topsheets, absorbent cores, front and/or back ears, fastener components, and various types of webs, including elastic webs, and components such as leg elastics, barrier leg cuffs, and waist elastics. Once the desired component parts are assembled, the advancing web(s) and component parts are subjected to a final knife cut to separate the web(s) into discrete diapers or other absorbent articles. The discrete diapers or absorbent articles may also then be folded and packaged.
As stated above, during the assembly process, component parts, such as elastic components, are used to manufacture diapers. Generally, the component parts are supplied on spools that comprise a core and a material wound around the core. Spools used in the manufacture of the absorbent articles are located adjacent to the manufacturing line on unwind stations. Traditionally, the unwind stations are large, occupying a substantial amount of floor space in the manufacturing facility. The large size of the unwind stations is also due in part to the need to operate at high manufacturing speeds and the relatively large amount of component material used in a single absorbent article. In order for manufactures to supply enough material to the manufacturing line, several spools of material must be stored adjacent to the line. Traditionally, unwind stations consist of spools mounted in vertical tiers. Each tier has at least two spools, an active spool and a reserve spool. The spools in the same tier are located adjacent one another in the same horizontal plane.
The active spool is unwound such that the elastic material may be fed through a control device such as a metering device or tension device. The control device is positioned between the active and reserve spools so that the elastic material is unwound at an angle. More specifically, the cores of each of the active spool and the reserve spool are not parallel to the control device. Having each spool at an angle to the control device allows manufacturers to switch to the reserve spool after the active spool has been depleted. For seamless transitions, manufactures connect the end of the active spool to the beginning of the reserve spool. The empty spool can then be removed and replaced with a new reserve spool. Thus, the unwind stations have to have sufficient room to load and unload the spools. The spools are loaded and unloaded by threading the core of the spool onto a spool holder, which is generally a fixed shaft. More specifically, the spool holder has an open portion adjacent to the control device where a spool can be loaded adjacent to the control device.
However, the use of unwind devices similar to the aforementioned have presented several problems. For example, unwind stations must be of sufficient size to handle multiple, vertical tiers of spools and tiers having at least an active spool and a replacement spool located horizontally and adjacent to one another. Thus, unwind stations have been large, taking up relatively large amounts of floor space in manufacturing facilities. Further, unwind stations must have sufficient room for operators to load and unload the spools from the portion of the spool holder adjacent to the control system. Further still, operators are required to load the unwind stations near the active unwinding of material. Thus, operators must be extremely careful when loading and unloading not to disrupt the material that is being unwound on the active spool. A disruption in the material can result in, for example, defective products and manufacturing down time.
Thus, a need exists for a method and an apparatus for unwinding material for absorbent articles that allows for a relatively smaller amount of floor space to be used and allows for loading of the unwinding station while reducing the potential for interfering with the unwinding of the active spool.